1. Field of the Invention
The present invention relates to data authenticity and more particularly to a mechanism for improving the authenticity of digital data such as recorded voice samples, video clips or still picture images etc.
2. Background of the Invention
Authentic digital data is of interest to many cases. It could be provided, for example, as Digital Evidence in a Court of Law to strengthen a case or to a Content Vendor/Host that demands proof of the authenticity of digital data when a user uploads digital content to the Host site.
Digital Data can easily be modified or misused to accomplish malice. The trust component present in current day devices is primarily software based, hence it is almost impossible to detect tamper of digital data as software itself is easy to modify.
The Digital Video Authenticator (DVA) addresses law enforcement concerns for a means to authenticate digital video (DV) so that it will be admissible and trusted as evidence in court. The DVA is a peripheral device attached to a commercial digital video recording device whose purpose is to generate and record authentication data simultaneously as DV is recorded by the video recording device. Verification of the authenticity of a DV sample is then accomplished using non-real-time software tools. The DVA system and method reads digital video (DV) data from a digital video recording device, parses the DV data into elements representing video, audio, control and timing data and creates digital signatures that can be used to validate the original DV tape. The combination of secure digital signatures and repeatability of the DV data stored on tape provides the basis for proving the original video has not been modified.
A system for time-stamping a digital document containing, for example, alphanumeric, video, audio, or pictorial data, protects the secrecy of the document text and provides a tamper-proof time seal establishing an author's claim to the temporal existence of the document. Initially, the document may be condensed to a single number by means of a one-way hash function, thereby fixing a unique representation of the document text. The document representation is transmitted to an outside agency where the current time is added to form a receipt. The agency then certifies the receipt by adding and hashing the receipt data with the current record catenate certificate which itself is a number obtained as a result of the sequential hashing of each prior receipt with the extant catenate certificate. The certified receipt bearing the time data and the catenate certificate number is then returned to the author as evidence of the document's existence. In later proof of such existence, the certificate is authenticated by repeating the certification steps with the representation of the alleged document, the alleged time data, and the catenate certificate number appearing in the agency's records immediately prior to the certificate number in question. Only if the alleged document is identical to the original document will the original and repeat certificate numbers match.
A digital video authenticator achieves the same level of authentication using signatures and copies of the captured data. However it is a well known fact that software cannot be trusted since it is a very achievable task to modify software. Also the interface between the Capturing device and the DVA needs to be secured. Any malware (software from an un-trusted vendor), residing on the capturing device can change the captured data and render it unfit for use as evidence in court. Accordingly an alternative for verifying the authenticity of Digital Data is needed.